Headphone



FIG. 1 is a front and right side perspective view of a headphone, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right-side elevational view thereof, the left-side being a mirror image thereof;

FIG. 5 is a top plan view thereof; and

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a headphone, as shown and described. 